<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CSS_元素的默认样式</title>
    <style>
        body {
            margin: 0;
        }

        #d1 {
            font-size: 50px;
            color: orange;
        }

        a {
            color: black;
            text-decoration: none;
            cursor: default;
        }
    </style>
</head>

<body>
    <div id="d1">
        <a href="https://www.baidu.com">去百度</a>
        <span>你好啊</span>
    </div>
    <hr>
    <h1>一级标题</h1>
    <h1>二级标题</h1>
    <hr>
    <p>我是一个段落</p>
    <hr>
    <ul>
        <li>张三</li>
        <li>李四</li>
    </ul>
</body>

</html>